This is has been solved, more or less, with assistance from oracle. It seems that CentOS created a default entry in /etc/hosts that included the machine name and domain name in the loopback entry. After editing those out, I installed oracle. All appeared to go well, however there was still a permissions issue. By runing netca to reconfigure the listener I was able to start a listener after this utility generated a new listener.ora. I still have to manually restart everything after reboot, but it appears that I have a functional oracle database.